典型钢铁生产流程理论极限能耗与CO_(2)排放分析

Analysis of theoretical limit energy consumption and CO_(2) emissions of a typical iron and steelmaking production process

高炉-转炉流程是钢铁生产的主要流程,该流程也是典型的铁-煤化工过程,其物质、能源消耗和CO_(2)排放一直居高不下,在双碳目标下,钢铁生产流程节能与CO_(2)排放面临巨大压力和挑战。因此,以典型高炉-转炉长流程炼钢以及电弧炉短流程炼钢工艺为基础的极致能耗和CO_(2)排放的研究具有重要意义。围绕钢铁生产过程反应机理,采用热力学和热化学理论,对相应的生产工艺进行假设,基于实际的原料、燃料参数和反应条件,从工序和全流程的角度计算了典型钢铁生产过程的理论极限能耗和理论CO_(2)排放量,并剖析了其影响因素。结果表明,轧制过程为冷装料情况下,原料为全铁水时高炉-转炉长流程的理论极限能耗(以标准煤计)和CO_(2)排放为389.29 kg/t和824.08 kg/t(以CO_(2)计);15%废钢比的条件下,高炉-转炉长流程的理论极限能耗(以标准煤计)和CO_(2)排放减少,为338.56 kg/t和681.30 kg/t(以CO_(2)计)。采用电炉短流程炼钢工艺时,钢铁生产过程的能耗进一步降低,如采用100%废钢时,短流程炼钢工艺的理论极限能耗(以标准煤计)和CO_(2)排放分别为72.76 kg/t和328.79 kg/t(以CO_(2)计);而当原料为DRI或铁水时,电炉炼钢工序的能耗减少,但不利于全流程能耗的降低。探讨了不同原料结构、冶炼工艺对全流程能耗和CO_(2)排放的影响,以期为钢铁生产流程极致能效、极限碳排放分析提供理论依据,从而挖掘典型钢铁生产流程节能降碳潜力,助力钢铁行业碳达峰碳中和目标实现。

The blast furnace-basic oxygen furnace process is a typical iron and steelmaking production process,which is also a typical iron-coal chemical process,and its material and energy consumption and CO_(2)emissions have been high.Under the double carbon target,the energy saving and CO_(2)emissions of the iorn and steelmaking production process are under great pressure and challenge.Therefore,the study of extreme energy consumption and carbon emission based on the typical BF-BOF long process steelmaking and the short process of electric arc furnace steelmaking have attracted attention.Based on the reaction mechanism of iorn and steelmaking production process,thermodynamic and thermochemical theories are used,assumptions are made for the corresponding production processes,and actual raw materials,fuel parameters and reaction conditions are used to calculate the theoretical limit energy consumption and theoretical CO_(2)emissions of typical iorn and steelmaking production processes from the perspective of process and the whole process.The theoretical limit energy consumption and CO_(2)emission of blast-converter long process are 389.29 kg/t and 824.08 kg/t(CO_(2))when the rolling process is cold charging and the raw material is all hot metal.Under the condition of 15%scrap ratio,the theoretical limit energy consumption and CO_(2)emission of BF-BOF long process are reduced to 338.56 kg/t and 681.30 kg/t(CO_(2)).The energy consumption of iron and iorn and steelmaking production is further reduced when the short process of electricarc furnace steelmaking is adopted.If 100%scrap is used,the theoretical limit energy consumption and CO_(2)emissions of the short-process steelmaking process are 72.76 kg/t and 328.79 kg/t(CO_(2)),respectively.When the raw material is DRI or hot metal,the energy consumption of the EAF steelmaking process is reduced,but it is not conducive to the reduction of the whole process energy consumption.In summary,the effects of different raw material structures and smelting processes on the energy consumption and CO_(2)emissions of the whole process are also discussed,in order to provide theoretical data for the analysis of extreme energy efficiency and extreme carbon emissions of iron and steelmaking production processes,so as to explore the energy saving and emission reduction potential of typical production processes and help the steel industry achieve its carbon neutrality goal.